... Next . 3.0.9 - 3.0.18 only, PHP 4 >= 4.0.0) mhash -- Compute hash . string mhash ( int hash, string data, string [ key ]) . mhash() applies a hash function specified by hash to the data and returns the resulting hash (also called digest). If the key is specified it will return the resulting HMAC. HMAC is keyed hashing for message authentication, or simply a message digest that depends on the specified key. Not all algorithms supported in mhash can be used in HMAC mode. ...